How to Plan a Building Extension Without Losing the Plot
So you’ve decided you want more space. Maybe it’s a bigger kitchen. Maybe you want French doors opening out onto a brand-new patio like the one above. Whatever the vision, the timeline isn’t instant, and the best results never are. Let’s walk through how long it actually takes to go from an idea to a finished build, without losing your mind in the middle.
Remember things like fire regulations when looking to design your new space, or at the stage of employing the services of an architect. Visit our contact page to get your extension conversation started. Or browse our project gallery for real-life inspiration from across Nottinghamshire and Derbyshire.
Build to Deadline Without Cutting Corners: Around 20 weeks
A standard single-storey extension, once we’re up and running, can take anywhere around 16 weeks depending on weather, scope, and finish level. Two-storey extensions? Closer to 20 weeks as a minimum time projection, as with all structural changes you’ll need to add time for roofers, electricians, plumbers, and joiners, all of whom need to be scheduled like a military operation!
We’ve done this hundreds of times across Mansfield, Nottinghamshire and Derbyshire. We manage it because we plan it like clockwork. From roofing to external fencing, we handle every trade with precision.
First Things First: Book Your Architect Before You Blink
The first person you’ll need is an architect or a designer—someone who can sketch your dream into technical drawings. The wait time for a good one? Anywhere between 2 and 6 weeks just to get booked in, especially around Mansfield, Sutton-in-Ashfield, and Hucknall. Once engaged, it takes another 2 to 4 weeks to draw up initial plans. If you’re in a conservation area like Edwinstowe or have quirks in your land like on a slope in Kirkby-in-Ashfield, budget even more time for that early-stage prep. Your architect should ideally liaise with your builder to make sure the design isn’t just pretty—it’s actually buildable within budget.
If you’re dreaming about summer barbecue parties on a freshly tiled patio, December is the ideal time to act, as you may be restricted with booking availability for a rushed decision. Contact an architect first of all to confirm your design needs. And start speaking to builders you trust, like Dave at Mansfield Buildworks. The sooner you slot into our diary, the sooner you’ll see bricks and progress and avoid delays and frustrations.
Planning Permission: The Silent Clock Ticker
If your extension falls outside permitted development, like a two-storey rear extension in Calverton or you’re converting a garage in Mansfield Woodhouse, you’ll need to apply for planning permission. That’s 8 weeks minimum. And yes, it’s 8 full weeks even if your neighbour signs off in five minutes. So get your paperwork in early, ideally the same day your architect finishes the drawings.
Now Book Your Builder (Yes, Before Permission is Granted)
Here’s the part most people don’t realise—builders book up fast. Like wedding venues and dentists who do Invisalign. If you’ve got your eye on a reputable builder like Buildworks Mansfield, book the slot even while your application is in motion. Most of our large-scale extension work in places like Clipstone, Arnold and Beeston is scheduled at least 2 to 4 months ahead. Sometimes longer in peak months. Waiting until you get permission is often too late to get the start date you want.
Groundwork, Materials, and the First Shovel in the Dirt
Once your start date is locked, allow a few weeks for site prep and material delivery. Builders don’t just rock up and start laying bricks. Especially if there’s demolition involved, or you’re extending into a garden with uneven levels like many homes in Farnsfield or Bilsthorpe. Our groundwork and stonework crew will usually arrive first for clearance, then drainage, before blockwork or foundation pours begin. At this stage, timing is everything. Delay your kitchen order, and we’re standing around. Delay your skip hire, and we can’t clear the site.